In the field of sports activities, of physiotherapy, of rehabilitation gymnastics and the like, machines for gymnastic exercises are known which make it possible to stretch various different muscle groups by acting on a single joint.
These known types of machine are not devoid of drawbacks, which include the fact that they are built to act only on one muscle group at a time without involving the other neighboring muscle groups in the exercise.
In particular, this drawback is relevant if one considers that some muscle groups, such as for example the muscles that belong to the posterior kinematic chain, as is known, are particularly subject to trauma, stress, fatigue and various disorders which are caused for example by incorrect postures assumed in everyday life or injuries of various kinds and, therefore, the stretching of a single muscle group might not be sufficient to achieve the sought beneficial goals.